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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Which earth for a SWA armouring? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1319736147 Message started by Flashbang on Oct 27^th, 2011, 6:22pm

Title: Which earth for a SWA armouring?
Post by Flashbang on Oct 27^th, 2011, 6:22pm

Hi
A 6mm2 2c SWA runs from the 32A MCB and RCD protected consumer unit in the property approx. 25-30mtrs to a medium size shed. The cable is to be buried and covered with tape and sand then back filled. At the shed will be a 'local' distribution board with its own RCD and MCBs feeding the lighting and up to six double sockets.
It has been suggested that at the shed end a separate earth rod should be installed to proved the main earth for the shed.

Question is..... which end of the SWA armouring should be connected to which earthing terminal - Main property, Shed end or both?

Title: Re: Which earth for a SWA armouring?
Post by Lectrician on Oct 27^th, 2011, 6:33pm

If you rod the shed, you must earth the SWA at the house end, isolating by glanding into a plastic enclosure or CU at the shed.

The SWA would be fed from a non-rcd protected way in the house.

This is only usually done with PME supplies, and even then is not strictly required unless there are extraneous conductive parts in the shed that require main protective bonding (and even then you could use 10mm SWA instead and bond them).

Title: Re: Which earth for a SWA armouring?
Post by CWatters on Oct 28^th, 2011, 10:39am

I forget who first pointed me to this link but perhaps worth putting in the FAQ.. It redirects to a .pdf file.

http://www.google.co.uk/url?sa=t&rct=j&q=electrical%2Binstallations%2Boutdoors%2Ba%2Bsupply%2Bto%2Ban%2Boutbuilding%2BIET&source=web&cd=1&ved=0CBwQFjAA&url=http%3A%2F%2Felectrical.theiet.org%2Fwiring-matters%2F16%2Felect-inst-outdoors.cfm%3Ftype%3Dpdf&ei=S3eqTvmSO4348QPX-92VCw&usg=AFQjCNHdTWfigRIv_mVA-SEjvMCbiYcuAw

Title: Re: Which earth for a SWA armouring?
Post by Flashbang on Oct 28^th, 2011, 1:54pm

Thanks chaps.
:)